Fix secondary values

pygal/ghost.py

@@ -85,8 +85,8 @@ class Ghost(object):
     def add_xml_filter(self, callback):
         self.xml_filters.append(callback)
 
-    def make_series(self, series):
+    def make_series(self, series, offset=0):
-        return prepare_values(series, self.config, self.cls)
+        return prepare_values(series, self.config, self.cls, offset)
 
     def make_instance(self, overrides=None):
         for conf_key in CONFIG_ITEMS:
@@ -98,7 +98,7 @@ class Ghost(object):
         self.config(**self.__dict__)
         self.config.__dict__.update(overrides or {})
         series = self.make_series(self.raw_series)
-        secondary_series = self.make_series(self.raw_series2)
+        secondary_series = self.make_series(self.raw_series2, len(series))
         self._last__inst = self.cls(
             self.config, series, secondary_series, self.uuid,
             self.xml_filters)

pygal/util.py

@@ -319,7 +319,7 @@ def safe_enumerate(iterable):
             yield i, v
 
 
-def prepare_values(raw, config, cls):
+def prepare_values(raw, config, cls, offset=0):
     """Prepare the values to start with sane values"""
     from pygal.serie import Serie
     from pygal.config import SerieConfig
@@ -404,7 +404,7 @@ def prepare_values(raw, config, cls):
         serie_config(**config.to_dict())
         serie_config(**serie_config_kwargs)
         series.append(
-            Serie(len(series), title, values, serie_config, metadata))
+            Serie(offset + len(series), title, values, serie_config, metadata))
     return series